We now know that the terminal equipment (eg mobile phones) on the use of all LPDDR, whose support rate is not lower than DDR, but there is a huge area and power consumption advantages, the agreement did not see what its performance gap, then why LPDDR not be used on the server and PC do? This article will from both theory and practice to explain why LPDDR not replace DDR use on the desktop.
ICMAX PC DDR
Theoretically
First, LPDDR performance relative to the performance of the desktop is not enough, although it LPDDR3 parameters brisk performance, but especially on the server PC side, almost all of RDIMM 128GB.
Secondly, DDR has ECC "error checking and correction", it can quickly check and correct the most common cause of data corruption that downtime and data loss.
ECC memory is important for cloud services and virtual machines. In fact, for large-scale cloud computing services and virtual machines more widely, it means that the server not only for large companies, for the average consumer is also very important. For example, your personal micro-channel and Baidu cloud, your valuable personal data storage server using ECC memory to prevent memory errors. Otherwise, you may not be able to access the data, and the worst case, cause data loss, you believe a lot of important micro-cloud data such as micro-channel wallet and address book will be missing.
Finally, LPDDR feet less than the pin DDR, leading to more shortages pin multiplexing relationship and timing constraints more demanding, in a mobile device, you can meet such high demands through close physical layout, but the desktop PC impossible to use such a small SOC. LPDDR3 is several times the cost of DDR4 other hand, the advantages are obvious at the same performance.
ICMAX LPDDR
Actually
Low Power means low power consumption, because the smart phone like a computer that can not provide continuous high voltage strength, so LPDDR memory only for mobile electronic devices, and the computer will continue to use the type of DDR memory, the performance difference is similar to the CPU chip Desktop and mobile versions, or graphics processor desktop and mobile versions, reducing its performance often be achieved by reducing power consumption, so the low-voltage version of the performance in general can not be compared with the normal voltage version of the performance.
As can be seen from the figure, two-channel 2133MHz LPDDR3 read, write, copy performance better than three single-channel DDR4 2666MHz, 2400MHz DDR4 tied dual-channel, dual channel weaker DDR4 2666MHz, latency is significantly larger than DDR4 difference LPDDR3 some. The reality is that many ultra-extreme LPDDR3 is still used, on the one hand is so compact motherboard is impossible to go out any space to place a DDR4 memory, another aspect that the processor does not support Intel LPDDR4.
So Wang-Wang semiconductor LPDDR generally used in mobile phones and ultra-thin notebooks, and DDR use on a desktop computer.